Displaying items by tag: oysters

China: Eaton and Langham hotels have collaborated with Green Island Cement to transform 8t of oyster shells into a sustainable cement alternative, sourcing 80% of the required limestone for cement.

Amie Lai Gor, general manager of sustainability at Great Eagle Holdings, parent company of the two hotels, said "We brought together like-minded partners to repurpose oyster shells as a sustainable raw material alternative for cement production. Our goal is to encourage more hotels and restaurants to participate, diverting more discarded oyster shells from landfills through upcycling.”

Raymond Cheung Wai-man, division manager at Green Island Cement, highlighted past challenges of separating the shells from impurities like mud and residual meat, which initially deterred the project.

Lai Gor added that future plans include working with local universities to assess the carbon reduction potential of substituting limestone with oyster shells in cement production. Despite the higher costs—tenfold compared to traditional limestone—Cheung believes that scaling up could significantly lower expenses.

US: A team at the University of Princeton has developed a new alternative cement using oyster shells. The team says that the oyster shells provide calcium carbonate in the form of aragonite, along with biopolymers. Together, these raise the resulting cement’s crack resistance by 19% and its ductility by 17% compared with ordinary Portland cement (OPC).

Team leader Reza Moini said “Our bio-inspired approach is not to simply mimic nature’s microstructure, but to learn from the underlying principles and use that to inform the engineering of human-made materials. One of the key mechanisms that makes a nacreous shell tough is the sliding of the tablet at the nanometer level. Here, we focus on the mechanism of tablet sliding by engineering the built-in tabulated structure of cement paste in balance with the properties of the polymer and the interface between them. In other words, we intentionally engineer defects in the brittle materials as a way to make them stronger by design.“